Modern excavating apparatus, such as the trencher and backhoe, are highly efficient in digging trenches and ditches. These apparatus require digging teeth of various different configurations made to initially engage the earth and remove increments therefrom as the teeth are forced to move in a particular manner. In a trencher, for example, a new set of teeth of proper design and construction will often enable several hundred feet of trench to be formed during the first few hours of operation. However, depending upon the characteristics of the removed earth, the teeth may rapidly wear and become dull, and often the efficiency of operation is reduced by fifty percent or so by the end of the second working day. It is not uncommon for the production rate of the excavated trench to be reduced to one-third of the production rate achieved during the first few hours of operation.
Therefore, on a trencher of the type having an endless chain to which there is attached a plurality of digging teeth, it is not uncommon to replace the teeth after only three days of operation, otherwise the digging apparatus is operating at only one-third efficiency. There may be 40 digging teeth on the trencher apparatus, and in order to replace the digging teeth, it may be necessary for two men to work for more than one-half day. Most prior art teeth usually are fabricated from a bent up piece of heat treated metal, having apertures formed therein by which each digging tooth is attached to the endless chain in spaced relationship respective to one another. The chain usually supports the digging teeth on alternate sides thereof, so that there must be right hand and left hand digging teeth spaced along the chain. Under conditions such as this, the expense involved in replacing the teeth is considerable because the entire tooth assembly must be removed and a new tooth substituted therefor. This action represents a considerable expense, as well as substantial loss in excavating time along with the cost of the labor required for replacing the teeth.
Accordingly, it would be desirable to have made available a new digging tooth assembly having a holder device rigidly attached to the digging apparatus which need not be replaced each time a tooth becomes worn. The holder device preferably removably receives a digging tooth therein which can be rapidly mounted to the holder device. Moreover, it would be desirable if the tooth and holder assembly was fabricated in a manner to enjoy a longer digging life as compared to most other prior art teeth. A digging tooth and holder assembly of this type is the subject of the present invention.